Upsilon1 Hydrae

For other stars with this Bayer designation, see υ Hydrae.
Upsilon1 Hydrae
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydra
Right ascension 09h 51m 28.69384s[1]
Declination −14° 50′ 47.7710″
Apparent magnitude (V) 4.12[2]
Characteristics
Spectral type G6/8III[3]
U−B color index +0.65[2]
B−V color index +0.92[2]
Astrometry
Radial velocity (Rv)−14.34[4] km/s
Proper motion (μ) RA: +18.88[1] mas/yr
Dec.: −21.85[1] mas/yr
Parallax (π)12.36 ± 0.26 mas[1]
Distance264 ± 6 ly
(81 ± 2 pc)
Absolute magnitude (MV)−0.43[5]
Details[4]
Mass3.33 M☉
Radius14.69 R☉
Luminosity162 L☉
Surface gravity (log g)2.95 cgs
Temperature5,185 K
Metallicity [Fe/H]0.10 dex
Rotational velocity (v sin i)2.11 km/s
Age270 Myr
Other designations
Zhang, upsilon1 Hya, 39 Hydrae, BD-14°2963, HD 85444, HIP 48356, HR 3903, SAO 155542
Database references
SIMBADdata

Upsilon1 Hydrae (υ1 Hydrae, abbreviated Ups1 Hya, υ1 Hya), also named Zhang,[6] is a yellow-hued star in the constellation of Hydra. It is visible to the naked eye, having an apparent visual magnitude of 4.12.[2] Based upon an annual parallax shift of 12.36 mas as seen from Earth,[1] it is located about 264 light-years from the Sun. The star is moving closer to the Sun with a radial velocity of −14.34 km/s.[4] In 2005 it was announced that it had a substellar companion.[7]

  1. ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  3. ^ Takeda; et al. (2008). "Stellar Parameters and Elemental Abundances of Late-G Giants". Publications of the Astronomical Society of Japan. 60 (4): 781–802. arXiv:0805.2434. Bibcode:2008PASJ...60..781T. doi:10.1093/pasj/60.4.781. S2CID 16258166.
  4. ^ a b c Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474, S2CID 53666931.
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  6. ^ "Naming Stars". IAU.org. Retrieved 16 December 2017.
  7. ^ Cite error: The named reference Sato et al. was invoked but never defined (see the help page).